Apparatus for cutting pre comminuted material into chips

ABSTRACT

Apparatus for cutting pre-comminuted material into chips. The apparatus includes an outer normally stationary cage which carries a plurality of normally stationary blade assemblies which circumferentially surround a rotor which carries rotary blades to coact with normally stationary blades of the cage. The several normally stationary blade assemblies which are carried by the cage can all be simultaneously locked or unlocked. When unlocked they can be individually removed in order to be selectively replaced. However, it is also possible to remove all of the normally stationary blade assemblies simultaneously when a ring of the cage is unlocked from a housing of the apparatus.

United States Patent [191 [111 3,746,269 Maier [451 July 17, 1973 [54] APPARATUS FOR CUTTING 2,851,256 9/1958 Androepoulos et al..... 241/285 B X PRE COMMINUTED MATERIAL INTO 2,857,110 10/1958 Clark 241/285 R X 2,874,909 2/1959 Pallmann 241/299 X CHIPS Inventor! Gerhard 11 Fichtestfasse, Primary Examiner-Granville Y. Custer, Jr.

4812-B1'ackwede, Germany Attorney-Steinberg & Blake [22] Filed: May 24, 1971 57 ABSTRACT [21] Appl. No.2 146,038 I 1 Apparatus for cutting pre-commmuted material into chips. The apparatus includes an outer normally sta- [30] Foreign Application Priority Data tionary cage which carries a plurality of normally sta- June 26, 1970 Austria 5782 ti nary blade assemblies which circumferentially surround a rotor which carries rotary blades to coact with [52] US. Cl 241/244, 24l/259.1, 241/285 A, normally stationary blades ofthe cage. The several nor- 241/299 mally stationary blade assemblies which are carried by [51] Int. Cl. B02c 13/06 he cage can all be simultaneously locked or unlocked. [58] Field of Search 241/228, 244, 255, When unlocked they can be individually removed in 241/285 R, 285 A, 285 B, 286, 299 Order to be selectively replaced. However, it is also possible to remove all of the normally stationary blade as- [56] References Cited semblies simultaneously when a ring of the cage is un- UNITED STATES PATENTS locked from a housing of the apparatus.

2,816,716 12/1957 Webb 241/285 B 9 Claims, 9 Drawing Figures .A" 10 f 47 53b Patented July 17, 1973 7 Sheets-Sheet 2 Gerhard Mai er BYI v/ a Ah neys Patented July 17, 1973 7 Sheets-Sheet 5 iNVliN'l'OR:

Gerhard Mai er y/fmla x 6M2 A zzorn e ys Patented July 17, 1973 3,746,269

7 Sheets-Sheet 4 INVliN'I'UR: Gerhard Maier Attorneys Patented July 17, 1973 3,746,269

'7 Sheets-Sheet 5 INVl-IN'I'UR:

Gerhard Maier Attor eys Patented July 17, 1973 3,746,269

7 Sheets-Sheet 6 INVEN'I'URI Gerhard Maier Atzor eys Patented July 17, 1973 3,746,269

7 Sheets-Sheet 7 INVEN'I'URI Gerhard Maier BY: jfim/ia Attorney$ APPARATUS FOR CUTTING PRE-COMMINUTED MATERIAL INTO CHIPS BACKGROUND OF THE INVENTION The present invention concerns a device for cutting up fragmented material such as pre-comminuted wood into chips. The device includes a comminuting chamber with a fixed knife cage having a plurality of knives, and splitting knives rotating within the knife cage and co-operating with the fixed knives thereof.

In some known devices for cutting wood into chips, difficult and time consuming dismantling of the entire knife cage is necessary when exchanging the knives. The dismantled knife cage is fitted with new or sharpened knives and installed again. Such exchange or replacement of the knives means that the device is out of action for a considerable time and involves accessories and labour It is also known to make individual knives of the cage such that they can be replaced within said cage; each knife is secured in position in the cage by its own locking device. When releasing the knives, several knives, combined in a group, are gradually removed from their holders by an extractor. Machine construction is complicated, and dismantling and reassembling of individual knives are difficult due to the many operations involved. Another disadvantage of known devices resides in the wedging of the knives in the cage as a result of expansion due to heat, which makes it extremely difficult to dismantle the knives immediately after use.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved comminuting device in which the blades are individually replaceable in a simple manner, and readily secured in the knife cage.

A further object is to provide the comminuting device with an unlocking and locking mechanism acting simultaneously on all the blades. At the same time, this mechanism prevents unintentional release of the individual blades and forms a means of assembly for securing said blade.

Moreover, the blades may be easily interchanged without the use of great force directly after use, when the machine is stationary.

In accordance with the invention an outer normally stationary cage means surrounds an inner rotor which carries a plurality of rotatable blade means. The cage means carries a plurality of normally stationary blade means with which the rotary blade means coact to cut pre-comminuted material into chips. The cage means is located within a housing and includes a pair of coaxial rings normally maintained stationary by a plurality of lock means which are carried by the housing and which coact with the rings for releasably locking them in stationary positions. The rings are supported for rotary movement so that when they are unlocked from the housing they can be rotated. The plurality of normally stationary blade means extend between the rings of the cage means and each normally stationary blade means includes a blade carrier extending between and directly connected to the rings and an assembly of a blade and bladeholding member carried by the blade carrier and removable therefrom. The assembly formed by the blade and blade-holding member can be releasably locked with respect to each blade carrier and one of the rings is formed with openings through which the assemblies of blades and blade-holding members can be removed after they are unlocked. However, the en tire set of normally stationary blade means together with one of the rings of the cage means can be removed while the other of the rings remains in the housing by removing from the housing a supporting ring with respect to which the one ring of the cage means is rotatable after unlocking this latter one ring from the support ring. The other ring of the cage means is also capable of being locked and unlocked so that when both rings are unlocked the entire cage means can be turned for situating the several blade means at suitable locations for individual removal and replacement.

BRIEF DESCRIPTION OF DRAWINGS An embodiment of the present invention is illustrated in the accompanying drawings in which:

FIG. 1 is a longitudinal section through a device for the splitting up of pre-comminuted wood into chips, comprising a conical knife cage secured against rotation by means of locking devices with individually extractable blade assemblies which are detachable and lockable by means of a common unlocking and locking mechanism.

FIG. 2 is a front view of the same device with the cover hood raised.

FIG. 3 is a longitudinal section through a portion of the same device at the area A of FIG. 1, showing the locking device stopping the knife cage, and the device for unlocking and locking the knife assembly.

FIG. 4 is a longitudinal section through a portion of the same device at the area B of FIG. 1 showing the locking device stopping the knife cage.

FIG. 5 is a front view of several blade assemblies inserted in the cage and secured by the unlocking and locking device, and also the locking device preventing the cage from turning, viewed in the direction of the arrow C in FIG. 1.

FIG. 6 is a perspective view of a portion of the cage, with a blade assembly formed of two rings, with blade supports holding the rings spaced from each other.

FIG. 7 is a perspective view of a blade support.

FIG. 8 is a perspective view of a blade assembly consisting of a holding plate and a cutting knife.

FIG. 9 is a cross section through a portion of the knife cage and through the rotor, with a splitting knife co-operating with the knife cage.

DESCRIPTION OF PREFERRED EMBODIMENTS A device according to the present invention for splitting up small pieces of material such as precomminuted wood, is provided with a stationary knife cage 11 in a housing 10 with a filling aperture 10a, and a rotor 12 extending into the knife cage 11 and rotating about a horizontal axis.

The knife cage 11 is provided with a plurality of knives or cutting blades I4 distributed over its circumference-and extending into the comminuting chamber 13 which is enclosed by the knife cage II. The knives I4 co-operate with splitting knives 12a provided on the rotor 12.

The normally stationary cage means II is composed of two coaxial rings 15, 16, mounted in the housing 10, and knife supports 17 equal to the number of knives and extending between the rings l5, 16. The knife supports 17 engage detachably in openings 19 of the two knife cage rings 15, 16, by means of bearing pins 18 provided at both ends of each support.

The knives 14 are mounted in the knife cage 11, and secured in position by means of a common locking device or means 20 so that they can be removed individually; at the same time all knife assemblies, each formed of a holding member (holding plate 21) and a cutting knife 14, are clamped in recesses 17a (see FIGS. 7-9) of the cage 11 and are releasable jointly, so that they can be removed individually, by means of unlocking and locking device 20.

The unlocking and locking device 20 is provided with a pressing ring 22 which is rotatable for unlocking and locking said knife assemblies, the ring 22 being provided on its circumference with an unlocking and locking bolt 23 for each knife assembly 14, 21; each bolt 23 of the pressing ring 22 engages in a slot 24 of a respective knife assembly 14, 21, which defines two parallel pressure surfaces 24a, 24b, of a slot 24 provided at an acute angle to the longitudinal direction of the knives (knife insertiondirection).

All the unlocking and locking bolts 23 are detachably secured to the pressure ring 22 from which they extend radially outwardly, and the slots 24 open towards one side portion of the knife assemblies 14, 21. Each slot is formed in a pressure plate 25 connected as by bolts 28a (FIG. 3) to the holding plate 21. y

The pressure ring 22 is acted upon by a thrustor 26 which can rotate the ring through a limited angle; the thrustor 26 is mounted at one end on an annular member 28 detachably connected to the knife cage ring 15, at the connecting point 27, and engages a bracket 30 secured to ring 22, by means of a pressure and draw bar 29. The thrustor 26 has an articulated connection at the linking point 31 between its rod 29 and the bracket 30 (see FIG.

The knife cage ring is provided with insertion openings 32 adjacent to the pressure ring 22 of a number equal to the number of knife assemblies 14, 21, through which openings the individual knife assemblies (holding plate 21 with cutting knife 14) are insertable in the recesses 17a of the knife supportl7 and removable therefrom.

The recess 17a of each knife support 17 is a slot extending in the longitudinal direction of the knife supports, andeach knife support 17 is provided with several, preferably 3, resilient pad means 33 located spaced apart in the longitudinal direction of the knife supports and pressing against the knife assembly 14, 21. Thus, the cage means 1 1 includes a plurality of normally stationary blade each composed of a carrier 17 and a blade assembly 14, 21 composed of the: blade 14 and the blade-holding member 21. The holding plate 21 of each knife assemblyis formed as shown in FIGS. 7-9, with a V-groove 21a receiving a key 21b of square cross section which is also received in a V-groove 210 formed in the inner surface of each wall 17!) of each carrier l7.

The pad means 33 are provided with pressure discs 34 the pressure of which is adjustable and bear against the holding member 21. Each pressure disc 34 is mounted in a recess 35 of a plug 36 threaded into an opening in wall 17b of the carrier 17; it is loaded by at least one cup spring 37 and held by a screw 38 for adjusting the pressure of the spring; the screw 38 passes freely through a hole in plug 36 and is screwed into the pressure disc 34 so that when the screw is turned, the

position of the pressure disc 34 in recess 35 of plug 36 is changed and the cup spring 37 is compressed more or less.

In order to increase the clamping connection between the holding plate 21 and pad means 33, the holding plate 21 is provided in the region of each disc 34 with an elastic contact surface 39 against which the resiliently secured pressure disc 34 is supported.

The knife cage 11 is of conical section and is prevented from rotating by means of locking devices 40, 41, pressing against the knife cage rings 15, 16.

The knife cage 11 and its two rings 15, 16 can rotate on bearing surface 42 (FIG. 3) of ring 47 having pairs of arms 47a interconnected by crosspieces 47h detachably connected by bolts 47c to inwardly extending portions 10b of the housing 10, so that it rings 15, 16 can be turned for interchanging the individual knife assemblies 14, 21.

The said assemblies may be brought sequentially to a convenient position. During operation the knife cage 1 1 is secured against rotation by the locking devices 40, 41. Several locking devices are spaced uniformly over the circumference of the cage 11.

Each locking device 40, (FIGS. 3 and 5) includes a cylinder and piston assembly 43a 440, the cylinder being fixed to the housing 10, with a holding member 45 pivotally secured to the piston 440 by a pin 45a and displaceable in an opening of ring 47 at a right angle, to the axis of rotation of the knife cage, in contact with the knife cage ring 15, to effect a clamping action. Thus holding members 45 of the locking devices 40 are displaceable at a right angle to the axis of rotation of the knife cage, and engage with a clamping effect between the knife cage ring 15 and external ring 47.

The surface of the ring 15 facing the housing ring 47 has an outwardly directed bevel surface 48 and the member 45 is provided with a wedge surface 49 cooperating with this bevel surface 48; other two surfaces of the holding member 45 and the ring 47 are formed so as to extend vertically parallel, so that the holding members 45 act as wedges between the two rings 15, 47, for securing the knife cage.

Releasable holding means 41 includes a number of cylinders 43b operatively connected with pistons 44b which are connected to the annular; holding member 46. The annular member 46 of the releasable holding means 41 which coacts with the ring 16 includes an outer ring 460 fixed to an inner 46b which is fixedly carried by the outer ring and which in turn is connected with the several pistons 44b which are displaceable parallel to the axis of rotation of the knife cage in response to movement of pressure fluid into and out of the cylinders 43b, and holding member 46 has a contact surface 50 co-operating with opposing surface 51 of the knife cage ring 16. These two co-operating surfaces 50, 51, are paralleL and perpendicular to the axis of rotation of the knife cage. The releasable holding means 46 engagesthe ring 16 and draws it with a clamping effect against the housing 10 so that the knife cage is secured here also (FIG. 4).

As is apparent from the above description in connection with FIGS. 1, 3, and 4, the ring 16 may be consid ered as permanently supported for rotary movement by the housing 10. While the ring 15 is supported for ro tary movement by the ring 47, this latter ring is detachably connected to the housing 10 by way of the screws 47c. The several fluid-pressure releasable lock means 40 serve to urge the ring toward the right, as viewed in FIGS. 1 and 3, and the ring 15 thus urges all of the normally stationary blade means, each composed of the carrier 17 and the blade assemblies 14, 21 carried thereby, longitudinally toward the ring 16 so that in this way in response to the action of the of the releasable lock means 40 the several stationary blade means are maintained stationary and fixed between the rings 15 and 16.

For rotating the knife cage to exchange the individual knife assemblies 14, 21, a motor 52 is provided which is mounted on the housing 10 and engages by means of a driving pinion 53 in a toothed crown wheel 54 connected to the knife cage ring 16.

The actuators 26, 43, may be hydraulic motors which receive their fluid from a common unit 55 (FIG. 2) by way of connecting lines.

The rotor 12, which is motor driven by its shaft 56, is provided with several recesses 12b in to which splitting knives l2a are detachably connected (FIG. 9); these knives 12a co-operate with the cutting knives 14 of the cage 11. Associated with each cutting knife 14 is an adjustable backing strip 57 determining with the cutting knife 14 the width of passage openings 57d and thus the thickness of the resultant chips. For example, as shown schematically in FIG. 9, the backing strips 57 may each be formed with a plurality of slots 57a, through which extend screws 57b which are threaded into the carriers 17 so that by loosening the screws 57b it is possible to shift the strips 57 in the direction indicated by the double-headed arrows 57c, and thus it is possible to adjust the width of the gaps 57d through which the chips fall in the direction indicated by the arrow X in FIG. 1 into a suitable receptacle situated beneath the structure of the invention which is illustrated in FIG.

The knife assemblies 14, 21, provided in the knife cage 11 are secured by the bolts 23 of the unlocking and locking device 20; these bolts 23 press against the surface 24a of each slot 24 of the knife assemblies 14, 21, and thus keep the knife assemblies in the recesses 17a of the knife supports 17.

In order to interchange the knife assemblies 14, 21, the pressure ring 22 is turned in the direction of the arrow A (see FIG. 6) by its thrustor motor 26; its bolt 23 now presses against the other pressure surfaces 24b of the slots 24 and at the same time draw all the knife assemblies 14, 21 simultaneously by a certain longitudinal amount out of the knife support recesses 17a. The pressure ring 22 is turned until its bolts 23 move out of the slots 24. g

In this position the individual knife assemblies 14, 21, are loosely disposed in the recesses 17a and can then beeasily removed manually from the knife cage 11 through the openings 32.

In order to be able to turn the knife cage 11 to a convenient place for removing the knife assemblies 14, 21, the locking devices 40, 41, are released after rotation of the pressure ring 22. Their holding members 45, 46 are displaced radially outwardly and axially, respectively, and their pressure surfaces 49, 50 unclamp from the annular surfaces 48, 51, so that the knife cage I] can be brought manually or by the motor 52 to the desired location.

The extracted knife assemblies 14, 21, are replaced by fresh knife assemblies with re-sharpened knives l4, and are inserted individually by hand through the openings 32 in the individual recesses 17a in the knife supports. After all the knife assemblies are replaced, the knife cage 11 is stopped. By the pressure of elements 44a, 44b of the actuators 43a, 43b, its two rings 15, 16 are re-clamped by the holding members 45, 46, again, and the knife cage 11 is secured so that it is unable to turn.

The clamping of the knife assemblies is now effected. The pressure ring 22 is turned by the thrustors 26 in the direction of the arrow B (see FIG. 6) so that its bolts 23 are introduced into the slots 24, and all the knife assemblies are simultaneously displaced longitudinally in the recesses 17a of the blade carriers 17.

The rib-like knife supports 17 forming the knife cage frame with the rings l5, 16, can be rapidly and simply changed without a screw connection when required. The individual knife supports 17 held in the two rings l5, 16 by bearing pins 18 can be easily extracted when the pressure ring 22 is opened, by removing the front ring 47 (after removing bolts 47c) and knife cage ring 15 with the several normally stationary blade means carried thereby from the other knife cage ring 16. At this time the releasable lock means formed by the pressure ring 22 and the pins 23 can remain engaged with the several blade means carried by the ring 15 so as to compel the several normally stationary blade means of the cage means 11 to be removed together with the ring 15 while the pins 18 at the right ends of the normally stationary blade means, as viewed in FIGS. 1 and 4, slip out of the openings 19 of the ring 16.

The assembly and dismantling of the knife supports 17 is facilitated by the rotor 12, since the latter rotates with a very small clearance in the knife cage 11 and thus provides a guide surface for the assembling and dismantling process of the knife supports 17.

In order to increase the clamping connection between the knife cage 11 and locking devices 40, 41, in the fixed position, the co-operating holding members 45, 46 and the surfaces of the rings l5, l6, and of the housing 10, 47 may be provided with resilient linings.

The housing 10 is provided with a pivotable cover hood 58 which can be locked manually or mechanically.

The locking and unlocking bolts 23 are made adjustable so that the pressure of the bolts 23 on the slots 24 can be adjusted and compensation of tolerances within the slots 24 can be equalised.

Each locking bolt part 23a (FIG. 3) engaging in the slot 24 is eccentric with respect to its part 23b secured in the pressing ring 22; thus adjustment is possible by the rotation of the bolt 23.

I claim:

I. In an apparatus for cutting pre-communited material into chips, housing means, rotary cutting means carried by said housing means for rotation about a predetermined axis and including a plurality of rotary blade means distributed about said axis, normally stationary cage means surrounding said rotary cutting means and carried by said housing, said cage means carrying a plurality of normally stationary blade means which coact with said plurality of rotary blade means to cut pre-comminuted material into chips, said cage means including a pair of rings supported for rotation by said housing, a plurality of blade carriers extending between and carried by said rings, and a plurality of blade assemblies respectively carried by said carriers and forming said normally stationary blade means therewith, one of said rings of said cage means carrying a releasable locking means which coacts with all of said blade asemblies for releasably locking the latter in operative positions carried by said plurality of carriers, respectively, and at least a pair of releasable holding means carried by said housing and coacting respectively with said rings for releasably holding the latter against rotation.

2. The combination of claim 1 and wherein said one ring is formed with openings through which said blade assemblies are respectively insertable into and removable from said carriers.

3. The combination of claim 2 and wherein each of said blade assemblies includes a blade member and a holding member for holding said blade member on said carrier, each holding member being formed at one end which projects through and beyond one of said openings of said one ring with an inclined slot, and said releasable locking means including a rotary pressure ring supported for rotation by said one ring and a plurality of lock pins extending radially from said pressure ring respectively into said slots of said holding members, and fluid-pressure means connected between said one ring and said pressure ring for rotating the latter in one direction to move said pins with respect to said slots for locking said blade assemblies in said operative positions carried by said carriers and in an opposite direction for moving said pins with respect to said slots for retracting said blade assemblies away from said operative positions partly out of said carriers, respectively.

4. The combination of claim 1 and wherein a turning means is operatively connected with the other of said rings of said cage means for turning the latter and the entire cage means therewith when said releasable holding means is actuated to release said cage means for rotary movement, so that the several normally stationary blade means can be located at a convenient location for removal and replacement 5. The combination of claim 1 and wherein'said releasable holding means includes fluid-pressure units and clamping components actuated thereby for clamping said rings to said housing.

6. The combination of claim 5 and wherein said normally stationary blade means are removably connected with the other of said rings, a support ring dctachably connected with said housing and supporting said one of said rings for rotary movement so that when the releas able holding means which coacts with said one ring is released for releasing the latter ring, said support ring and said one ring can be removed with all of said normally stationary blade means carried thereby and sepa rated from the other ring while the latter remains connected with said housing.

7. The combination of claim 1 and wherein each of said blade assemblies includes a blade member and a holding member for holding said blade member on said carrier and each of said normally stationary blade means including at its carrier a plurality of resilient units pressing against said holding member to press the latter against said blade member of each blade assembly.

8. The combination of claim 7 and wherein each of said resilient units includes a plug threaded into a wall of each carrier and having a hollow interior, a pressure disc situated in said hollow interior, and adjustable spring means pressing said disc against said holding member.

9. The combination of claim land wherein elastic linings are carried by said rings at the regions where the latter are engaged by said holding means. 

1. In an apparatus for cutting pre-communited material into chips, housing means, rotary cutting means carried by said housing means for rotation about a predetermined axis and including a plurality of rotary blade means distributed about said axis, normally stationary cage means surrounding said rotary cutting means and carried by said housing, said cage means carrying a plurality of normally stationary blade means which coact with said plurality of rotary blade means to cut precomminuted material into chips, said cage means including a pair of rings supported for rotation by said housing, a plurality of blade carriers extending between and carried by said rings, and a plurality of blade assemblies respectively carried by said carriers and forming said normally stationary blade means therewith, one of said rings of said cage means carrying a releasable locking means which coacts with all of said blade asemblies for releasably locking the latter in operative positions carried by said plurality of carriers, respectively, and at least a pair of releasable holding means carried by said housing and coacting respectively with said rings for releasably holding the latter against rotation.
 2. The combination of claim 1 and wherein said one ring is formed with openings through which said blade assemblies are respectively insertable into and removable from said carriers.
 3. The combination of claim 2 and wherein each of said blade assemblies includes a blade member and a holding member for holding said blade member on said carrier, each holding member being formed at one end which projects through and beyond one of said openings of said one ring with an inclined slot, and said releasable locking means including a rotary pressure ring supported for rotation by said one ring and a plurality of lock pins extending radially from said pressure ring respectively into said slots of said holding members, and fluid-pressure means connected between said one ring and said pressure ring for rotating the latter in one direction to move said pins with respect to said slots for locking said blade assemblies in said operative positions carried by said carriers and in an opposite direction for moving said pins with respect to said slots for retracting said blade assemblies away from said operative positions partly out of said carriers, respectively.
 4. The combination of claim 1 and wherein a turning means is operatively connected with the other of said rings of said cage means for turning the latter and the entire cage means therewith when said releasable holding means is actuated to release said cage means for rotary movement, so that the several normally stationary blade means can be located at a convenient location for removal and replacement.
 5. The combination of claim 1 and wherein said releasable holding means includes fluid-pressure units and clamping components actuated thereby for clamping said rings to said housing.
 6. The combination of claim 5 and wherein said normally stationary blade means are removably connected with the other of said rings, a support ring detachably connected with said housing and supporting said one of said rings for rotary movement so that when the relEasable holding means which coacts with said one ring is released for releasing the latter ring, said support ring and said one ring can be removed with all of said normally stationary blade means carried thereby and separated from the other ring while the latter remains connected with said housing.
 7. The combination of claim 1 and wherein each of said blade assemblies includes a blade member and a holding member for holding said blade member on said carrier and each of said normally stationary blade means including at its carrier a plurality of resilient units pressing against said holding member to press the latter against said blade member of each blade assembly.
 8. The combination of claim 7 and wherein each of said resilient units includes a plug threaded into a wall of each carrier and having a hollow interior, a pressure disc situated in said hollow interior, and adjustable spring means pressing said disc against said holding member.
 9. The combination of claim 1 and wherein elastic linings are carried by said rings at the regions where the latter are engaged by said holding means. 